scholarly journals Modeling suspended sediment sources and transport in the Ishikari River Basin, Japan using SPARROW

2014 ◽  
Vol 11 (10) ◽  
pp. 11037-11069
Author(s):  
W. Duan ◽  
B. He ◽  
K. Takara ◽  
P. Luo ◽  
D. Nover ◽  
...  
Keyword(s):  
Suspended Sediment ◽  
River Basin ◽  
Spatial Data ◽  
Agricultural Land ◽  
Prediction Errors ◽  
Watershed Model ◽  
Agricultural Lands ◽  
Stream Channels ◽  
Small Stream ◽  
Natural Logarithm

Abstract. It is important to understand the mechanisms that control suspended sediment (SS) fate and transport in rivers as high suspended sediment loads have significant impacts on riverine hydroecology. In this study, the watershed model SPARROW (SPAtially Referenced Regression on Watershed Attributes) was applied to estimate the sources and transport of SS in surface waters of the Ishikari River Basin (14 330 km2), the largest watershed on Hokkaido Island, Japan. The final developed SPARROW model has four source variables (developing lands, forest lands, agricultural lands, and stream channels), three landscape delivery variables (slope, soil permeability, and precipitation), two in-stream loss coefficients including small stream (streams with drainage area < 200 km2), large stream, and reservoir attenuation. The model was calibrated using measurements of SS from 31 monitoring sites of mixed spatial data on topography, soils and stream hydrography. Calibration results explain approximately 95.96% (R2) of the spatial variability in the natural logarithm mean annual SS flux (kg km−2 yr−1) and display relatively small prediction errors at the 31 monitoring stations. Results show that developing-land is associated with the largest sediment yield at around 1006.27 kg km−2 yr−1, followed by agricultural-land (234.21 kg km−2 yr−1). Estimation of incremental yields shows that 35.11% comes from agricultural lands, 23.42% from forested lands, 22.91% from developing lands, and 18.56% from stream channels. The results of this study improve our understanding of sediments production and transportation in the Ishikari River Basin in general, which will benefit both the scientific and the management community in safeguarding water resources.

scholarly journals Modeling suspended sediment sources and transport in the Ishikari River basin, Japan, using SPARROW

2015 ◽  
Vol 19 (3) ◽  
pp. 1293-1306 ◽  
Author(s):  
W. L. Duan ◽  
B. He ◽  
K. Takara ◽  
P. P. Luo ◽  
D. Nover ◽  
...  
Keyword(s):  
Suspended Sediment ◽  
River Basin ◽  
Spatial Data ◽  
Agricultural Land ◽  
Prediction Errors ◽  
Watershed Model ◽  
Agricultural Lands ◽  
Stream Channels ◽  
Natural Logarithm ◽  
Small Streams

Abstract. It is important to understand the mechanisms that control the fate and transport of suspended sediment (SS) in rivers, because high suspended sediment loads have significant impacts on riverine hydroecology. In this study, the SPARROW (SPAtially Referenced Regression on Watershed Attributes) watershed model was applied to estimate the sources and transport of SS in surface waters of the Ishikari River basin (14 330 km2), the largest watershed in Hokkaido, Japan. The final developed SPARROW model has four source variables (developing lands, forest lands, agricultural lands, and stream channels), three landscape delivery variables (slope, soil permeability, and precipitation), two in-stream loss coefficients, including small streams (streams with drainage area < 200 km2) and large streams, and reservoir attenuation. The model was calibrated using measurements of SS from 31 monitoring sites of mixed spatial data on topography, soils and stream hydrography. Calibration results explain approximately 96% (R2) of the spatial variability in the natural logarithm mean annual SS flux (kg yr−1) and display relatively small prediction errors at the 31 monitoring stations. Results show that developing land is associated with the largest sediment yield at around 1006 kg km−2 yr−1, followed by agricultural land (234 kg km−2 yr−1). Estimation of incremental yields shows that 35% comes from agricultural lands, 23% from forested lands, 23% from developing lands, and 19% from stream channels. The results of this study improve our understanding of sediment production and transportation in the Ishikari River basin in general, which will benefit both the scientific and management communities in safeguarding water resources.

Estimating the Sources and Transport of Nitrogen Pollution in the Ishikari River Basin, Japan

2012 ◽  
Vol 518-523 ◽  
pp. 3007-3010 ◽  
Author(s):  
Wei Li Duan ◽  
Bin He ◽  
Kaoru Takara ◽  
Ping Ping Luo ◽  
Yosuke Yamashiki
Keyword(s):  
River Basin ◽  
Surface Waters ◽  
Spatial Data ◽  
Point Sources ◽  
Drainage Network ◽  
Watershed Model ◽  
Order Stream ◽  
First Order ◽  
The Mean ◽  
Hokkaido Island

The hybrid mechanistic-statistical watershed model SPARROW (Spatially Referenced Regression on Watershed Attributes) was applied to estimate the sources and transport of total nitrogen (TN) in surface waters of Ishikari River Basin (14,330 km2), the largest watershed on the Hokkaido Island of Japan. The loads from atmospheric deposition, point sources and erosion are routed through the drainage network (900 streams) with first-order stream decay. Then we calibrated the model using measurements of TN from 31 monitoring sites of mixed spatial data on topography, soils and stream hydrography. The R2 and MSE are 0.82 and 0.62 separately. On this basis, the predication of TN distribution was evaluated, and the mean incremental annual TN yield was 11.61kg/ha/yr.

Conflicts caused by afforestations of agricultural land in densely populated areas

1991 ◽  
Vol 56 ◽  
Author(s):  
N. Lust ◽  
B. Muys
Keyword(s):  
Nature Conservation ◽  
Agricultural Land ◽  
Agricultural Lands ◽  
Biological Value ◽  
Ecological Problems ◽  
The Subject ◽  
Points Of View

In  densely populated areas, such as Flanders, serious conflicts arise due to the  afforestation of agricultural lands. Roughly speaking, three sectors are  involved: agriculture, forestry and nature conservation. These groups do not  always share the same points of view. But even within the different sectors  there are several subgroups with their own interests and approaches.  Generally speaking, agriculture is strongly opposed, forestry has a  relatively diversified meaning, whereas nature conservation is either opposed  or in favour, depending on the region's biological value.     The policy in this matter is not forest friendly. Legislation strongly  hampers the afforestation of agricultural lands. Moreover the subject leads  to a series of ecological problems, which have not really been considered up  to now.

scholarly journals Superiority of Hybrid Soft Computing Models in Daily Suspended Sediment Estimation in Highly Dynamic Rivers

2021 ◽  
Vol 13 (2) ◽  
pp. 542
Author(s):  
Tarate Suryakant Bajirao ◽  
Pravendra Kumar ◽  
Manish Kumar ◽  
Ahmed Elbeltagi ◽  
Alban Kuriqi
Keyword(s):  
Time Series ◽  
Wavelet Transform ◽  
Suspended Sediment ◽  
River Basin ◽  
Time Series Data ◽  
Series Data ◽  
Discrete Wavelet ◽  
Original Time Series ◽  
Inference System ◽  
Original Time

Estimating sediment flow rate from a drainage area plays an essential role in better watershed planning and management. In this study, the validity of simple and wavelet-coupled Artificial Intelligence (AI) models was analyzed for daily Suspended Sediment (SSC) estimation of highly dynamic Koyna River basin of India. Simple AI models such as the Artificial Neural Network (ANN) and Adaptive Neuro-Fuzzy Inference System (ANFIS) were developed by supplying the original time series data as an input without pre-processing through a Wavelet (W) transform. The hybrid wavelet-coupled W-ANN and W-ANFIS models were developed by supplying the decomposed time series sub-signals using Discrete Wavelet Transform (DWT). In total, three mother wavelets, namely Haar, Daubechies, and Coiflets were employed to decompose original time series data into different multi-frequency sub-signals at an appropriate decomposition level. Quantitative and qualitative performance evaluation criteria were used to select the best model for daily SSC estimation. The reliability of the developed models was also assessed using uncertainty analysis. Finally, it was revealed that the data pre-processing using wavelet transform improves the model’s predictive efficiency and reliability significantly. In this study, it was observed that the performance of the Coiflet wavelet-coupled ANFIS model is superior to other models and can be applied for daily SSC estimation of the highly dynamic rivers. As per sensitivity analysis, previous one-day SSC (St-1) is the most crucial input variable for daily SSC estimation of the Koyna River basin.

scholarly journals Insights on the Impacts of Hydroclimatic Extremes and Anthropogenic Activities on Sediment Yield of a River Basin

Earth ◽  
2021 ◽  
Vol 2 (1) ◽  
pp. 32-50
Author(s):  
Rocky Talchabhadel ◽  
Jeeban Panthi ◽  
Sanjib Sharma ◽  
Ganesh R. Ghimire ◽  
Rupesh Baniya ◽  
...  
Keyword(s):  
Suspended Sediment ◽  
River Basin ◽  
Extreme Precipitation ◽  
Suspended Sediment Concentration ◽  
Anthropogenic Activities ◽  
Sediment Concentration ◽  
Sediment Flux ◽  
Mountain River ◽  
Ecological Processes ◽  
Precipitation Indices

Streamflow and sediment flux variations in a mountain river basin directly affect the downstream biodiversity and ecological processes. Precipitation is expected to be one of the main drivers of these variations in the Himalayas. However, such relations have not been explored for the mountain river basin, Nepal. This paper explores the variation in streamflow and sediment flux from 2006 to 2019 in central Nepal’s Kali Gandaki River basin and correlates them to precipitation indices computed from 77 stations across the basin. Nine precipitation indices and four other ratio-based indices are used for comparison. Percentage contributions of maximum 1-day, consecutive 3-day, 5-day and 7-day precipitation to the annual precipitation provide information on the severity of precipitation extremeness. We found that maximum suspended sediment concentration had a significant positive correlation with the maximum consecutive 3-day precipitation. In contrast, average suspended sediment concentration had significant positive correlations with all ratio-based precipitation indices. The existing sediment erosion trend, driven by the amount, intensity, and frequency of extreme precipitation, demands urgency in sediment source management on the Nepal Himalaya’s mountain slopes. The increment in extreme sediment transports partially resulted from anthropogenic interventions, especially landslides triggered by poorly-constructed roads, and the changing nature of extreme precipitation driven by climate variability.

ANALYSIS OF DYNAMICS OF LAND USE STRUCTURE AND SOIL FERTILITY INDICATORS OVER THE KLYAZMA RIVER BASIN

2021 ◽  
pp. 88-98
Author(s):  
I.N. Kurochkin ◽  
◽  
E.Yu. Kulagina ◽  
N.V. Chugay ◽  
◽  
...  
Keyword(s):  
Land Use ◽  
Soil Fertility ◽  
River Basin ◽  
Agricultural Land ◽  
Remote Sensing Data ◽  
Livestock Grazing ◽  
Land Use Structure ◽  
Vladimir Region ◽  
Fallow Lands ◽  
Analysis Of Dynamics

The main trends in changing the land use structure in the territory of the Klyazma River basin were de-scribed in the article. Using GIS technologies and remote sensing data the areas of land with different land use regimes in the studied territory were determined in the period from 2001 to 2019. The indices of LAI and FPAR phytoproductivity for the territory of the Klyazma basin as a whole, and for each basin included in it were determined. The analysis of the dynamics of changes occurring in the structure of land use is carried out. For the territory of Vladimir region, which is a part of the Klyazma River basin, an assessment of soil types distribution over occupied area was carried out. An integral indicator of soil fertility was calcu-lated on the basis of statistical data of agrochemical indicators. The fraction of fallow lands decreased by 2019 and it amounts 33.76% of the total area of the studied territory. The fraction of mixed forests increased from 38.48% in 2001 to 44.50% in 2019 due to the formation of fast-growing tree species shoots on fallow lands. The area of meadow vegetation for the period from 2015 to 2019 decreased by 3.5%, from 4 276 to 3 121 km2, due to agriculture degradation and a significant decrease in livestock grazing. The indicator of soil fertility for the Klyazma basin was 0.74, which is a high indicator. It is established that the most active decrease in the agricultural land area occurs in the central, north-western and western parts of the river basin.

Denmark: experience of market turnover of agricultural land

Ekonomika APK ◽  
2021 ◽  
Vol 317 (3) ◽  
pp. 89-96
Author(s):  
Ihor Yurchenko
Keyword(s):  
Structural Model ◽  
Agricultural Land ◽  
Legal Framework ◽  
Empirical Method ◽  
Practical Significance ◽  
Agricultural Lands ◽  
Logical Scheme ◽  
Logical Method ◽  
Danish Experience ◽  
The Right

The purpose of the article is to reveal the experience of the functioning of the market circulation of agricultural land in Denmark, in order to further implement in Ukrainian practice, the positive and avoid negative aspects of this experience. Research methods. The study used an empirical method (comprehensive assessment of the modern model of market turnover of agricultural land in Denmark); generalization and systematization (construction of the concept and logical-structural model of economic turnover of lands); abstract-logical method (theoretical generalizations and formulation of conclusions). Research results. It was found that the tightly regulated market turnover of agricultural land in Denmark was changed to a more liberal one, with permission to buy land for foreigners, but this not only did not attract investment as expected, but on the contrary, led to even more negative and crisis phenomena in country. The main tools, mechanisms and conditions of land turnover in agriculture of this country are determined. Scientific novelty. The main purpose of regulating the market turnover of land in Danish agriculture has been established. The legal framework of Denmark for regulating the market circulation of agricultural land has been studied. The structural and logical scheme of market circulation of agricultural lands is formed. The provisions on the Ukrainian model of regulating the market turnover of agricultural lands were further developed, taking into account the experience of the studied country. Practical significance. The results of the study of the experience of the Kingdom of Denmark on the market turnover of land, in terms of granting non-residents access to the right to purchase agricultural land, is a clear practical answer and a caveat that should undoubtedly be taken into account in Ukraine. The application of the Danish experience should help to build an effective model of market turnover of agricultural land in our country. Tabl.: 1. Figs.: 1. Refs.: 18.

Sign in / Sign up

Export Citation Format

Share Document